title: Effect of synchronization of follicle-wave emergence with estradiol and progesterone and superstimulation with follicle-stimulating hormone on milk estrogen concentrations in dairy cattle.
abstract: Very little is known about the effects of hormonal synchronization of follicle waves and superovulation on the estrogen content of a cow's milk. The objective of this study was to determine the effect in dairy cows of synchronization with estradiol-17β (E2) and progesterone (P4) on milk E2 concentrations and to compare these levels with those achieved during superstimulation for 4 d with porcine follicle-stimulating hormone (FSH). The milk E2 concentrations were raised significantly above pretreatment levels (P < 0.05) for 2 d after synchronization, the mean peak being 40.2 ± 18.5 (standard error) pg/mL and the pretreatment mean 1.5 ± 0.5 pg/mL. The mean peak E2 concentration during ovarian stimulation was 4.4 ± 0.7 pg/mL. The mean E2 concentration was significantly higher (P < 0.05) after synchronization than during superstimulation for the 1st milking after synchronization but not subsequent milkings. The milk estrone concentrations were above pretreatment levels for 1 d after synchronization and were not different from those observed during superstimulation.
authors.affiliation: Centre de recherche en reproduction animale, Faculté de médecine vétérinaire, Université de Montréal, 3200, rue Sicotte, Saint-Hyacinthe, Québec J2S 7C6, Canada.
authors.forename: Lucilene B
authors.initials: LB
authors.lastname: de Souza
authors.forename: Raynald
authors.initials: R
authors.lastname: Dupras
authors.forename: Louis
authors.initials: L
authors.lastname: Mills
authors.forename: Younès
authors.initials: Y
authors.lastname: Chorfi
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Price
mesh_terms: D000818:Animals; D002417:Cattle; D003612:Dairying; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D004958:Estradiol / Q000008:administration & dosage / Q000494:pharmacology*; D004967:Estrogens / Q000737:chemistry* / Q000378:metabolism; D005260:Female; D005640:Follicle Stimulating Hormone / Q000008:administration & dosage / Q000494:pharmacology; D008892:Milk / Q000737:chemistry*; D006080:Ovarian Follicle / Q000187:drug effects* / Q000502:physiology; D011374:Progesterone / Q000008:administration & dosage / Q000494:pharmacology*; D013480:Superovulation / Q000187:drug effects
chemical_list: D004967:Estrogens; D011374:Progesterone; D004958:Estradiol; D005640:Follicle Stimulating Hormone